Can anyone tell me there method of maintaining batteries during winter storage? I use a BMW trickle charger that was designed to plug into a lighter receptacle. But with the dual battery system of the CLS I doubt it will work as desired.

It comes with clamps too, so I was wondering, what do you guys do to keep them charged?

Thanks

 

A trickle charger that is not automatic, is not a good solution for a car / boat / RV in long term storage. The most desirable is a 1-2 amp fully automatic charger that can be permanently installed, like this one. I am partial to "Marine Grade" or solid state equipment and I would avoid any cheap charger.
http://store.schumachermart.com/se-1-12s.html
I currently use 8 of the Schumacher auto chargers, they work great. One other consideration is the 110V input, I use a high quality surge protector on the 110V AC side and a timer to avoid having the charger on line during thunder / electrical storms that form up in the after noon, here in Florida. The lighting capitol of the world.

 

I probably shouldn't have referred to it as a trickle charger. I simply meant it was a low amperage charger/maintainer. According to BMW it's designed to be left on all winter if necessary.

This is the unit ..


My question is, with the dual battery system, how are guys maintaining these? 2 chargers? Alternate charging? I'm wondering what method others have had success with.

Thanks for the reply.

 

The battery control module keeps the SBC battery charged from the larger rear start battery.
That said there are a few issues that will need to be addressed.
1. The cigarette lighter needs to be switched to always on.

2. How to get the 110 V inside the car, I need to lock my car so
that is an issue. You may be able to leave a window down.

 

I have a battery tender hard wired to my rear battery in my SL600. When I don't drive the car for extended periods of time, I simply plug it into an outlet in my garage. Couldn't be simpler.

 

Thanks YachtMaster ... that's what I needed to know.

My car is in my garage, so leaving it unlocked isn't an issue. So it sounds like I can just install this charger on the rear battery and it will keep both charged? Is that correct?

 

Does that car have the second battery up front? And if so, does this set up keep both charged?

 

Yes it has a second battery up front. I wanna say that battery is for starting the car only, while the rear battery does everything else (consumer electronics). Not sure if it charges both. But after the car sat for 3 weeks in the bitter cold, she fired right up and I didn't have the infamous "consumer electronics offline" message.

 

Sorry to ressurect this old thread BUT i have a question!

I just read my CLS55 Manual and it states that is is FORBIDDEN to charge the battery outright , when it is connected to the car. To charge the battery it must first be disconnected and removed from the car. Doesnt your manual state the same? if it does, have you had any problems with consuemr electronics in your car?